No. 28: Cynicism

Alice: We have to remember that money can't buy happiness.
Mr. Wilson: You think I don't already know this?

The author writes:

The original strip's punchline was pretty lackluster, so I decided to replace it with one that's a lot more world-weary. (Honestly, legacy strips like these lend themselves so well to mockery - just look at Bill Watterson's "Cheapening of the Comic" speech, or any of the many other parodies out there.)